Sharp Kabushiki Kaisha Corporation

Other

Sharp Corporation

Mitsubishi Metal Corporation

Sharp Kabushiki Kaisga

Yoshiteru Murakami

Akira Takahashi

Kenji Ohta

Junji Hirokane

Hiroyuki Katayama

Junichiro Nakayama

Naoyasu Iketani

Michinobu Mieda

Junsaku Nakajima

Go Mori

Shigemi Maeda

Hideharu Tajima

Masaki Yamamoto

Yasuhiro Harada

Tetsuya Inui

Hirohisa Yamada

Tomoyuki Miyake

Toshihiko Sakai

Kazuo Van

Noboru Iwata

Ikuo Nakano

Hideaki Sato

Shintaro Miyanishi

Ippei Suzuki

Toshihisa Deguchi

Nobuyuki Takamori

Tomoki Ono

Toshikazu Nagaura

Masayasu Futagawa

Shinji Yamagami

Hiroyuki Ikenaga

Junji Hirogane

Junichi Sato

Kunio Kojima

Yasushi Ogimoto

Tazuko Kitazawa

Hideyoshi Yamaoka

Teruhisa Kotani

Yoshikazu Fujii

Kenichi Hijikata

Hirotaka Toki

Shinya Hirata

Hideki Eto

Kousuke Innami

Takyuki Shingyoji

Kazushige Takaishi

Kouji Ohta

Junsaku Nakayima

Ichiro Hiramatsu

An antireflective structure having a higher antireflective effect compared with those of conventional antireflective structures is produced by a simple process. The antireflective structure () includes a plurality of concavities () each having a plurality of convexities () thereon, and a pitch between the plurality of convexities () and a pitch between the plurality of concavities () are smaller than a wavelength of light incident to the antireflective structure ().

Optical element, and antireflective structure and process for production thereof

In an optical information storage medium reproduction apparatus reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus requires.

Optical information storage medium reproduction apparatus and control method of the same

In information recording areas of a disc-shaped magnetic recording medium, recording columns adjacent to each other relative to a radial direction are formed to partially overlap with each other in the radial direction. A first recording and a second recording are selectively performed. In the first recording, a first recording column, a second recording column (the outer adjacent recording column of the first recording column) and a third recording column (the outer adjacent recording column of the second recording column) are formed so that the radial positions of the inner and outer circumferential edges of the first recording column, those of a second recording column, and those of a third recording column satisfy R&#x3c;R&#x3c;R&#x3c;R&#x3c;R&#x3c;R. In the second recording, a non-overlapping portion which does not overlap with any of the recording columns in the radial direction is formed on each of the recording columns.

Magnetic recording reproducing apparatus and magnetic recording medium

A magnetic recording element records information by applying a recording magnetic field to a magnetic recording medium having an information recording area to form a plurality of recording columns extending in a first direction. Recording by the magnetic recording element is performed so that a first recording column and a second recording column formed before the first recording column partially overlap each other in a second direction perpendicular to the first direction, and that a recording start position of the first recording column is positioned upstream, relative to the recording direction, of a recording start position of the second recording column.

Recording reproducing apparatus and magnetic recording medium

In an optical information storage medium reproduction apparatus for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus requires.

Disclosed is a magnetic recording/reproduction deviceincluding: a recording/reproduction head; and a recording/reproduction headfor detecting a leakage magnetic field of each of the plurality of magnetic recording cellsso as to reproduce information, the recording/reproduction headcarrying out the recording on the magnetic recording mediumso that the magnetic recording mediumincludes continuous recording regions that (i) satisfy N&#x2267;2 and that (ii) include a continuous recording region that satisfies N&#x2260;n&#xd7;N, where N represents a number of magnetic recording cellsin a continuous recording region; Nrepresents a minimum value for N; and n represents a positive integer, the continuous recording regions each being a region on a reproduction track in which region magnetic recording cellssharing an identical magnetization direction are sequentially arranged in a circumferential direction of the magnetic recording medium

Magnetic recording/reproduction device and magnetic recording medium

This invention allows super-resolution reproduction with which a better bER value is attainable, when information is recorded by a random pattern including a mark length not longer than a resolution limit, by use of a highly versatile signal decoding method. Information is recorded as marks and spaces coded by RLL(1,7) modulation, which each of the marks and spaces have one of a plurality of lengths, and 2T marks and 2T spaces of the marks and spaces being formed are shorter than 0.12 &#x3bc;m. An information recording layer () includes a reproduction film () and a reflective film () which are provided in this order from a side from which reproducing light is incident, which reproduction film is made of (i) zinc oxide, (ii) strontium titanate, (iii) titanium oxide, (iv) cerium oxide, or (v) a material including at least one of the (i) through (iv), and which reflective film is made of tantalum or titanium.

Optical information recording medium and optical information processing apparatus

A magnetic recording/reproducing apparatusincludes: a magnetic head; a magnetic recording medium; a spindleand a spindle motor; a suspension arm; a voice coil motor; and a control unit. The control unithas: a motor driver; a head amplifier; a read/write channel; a laser driver; and a controller. The controllerhas: a preliminary recording unit; a judgment unit; an extraction unit; a drive condition determining unit; and a preliminary recording terminating unit. Based on a reproduction signal evaluation value obtained using these units and a predetermined reference value, a drive condition is determined which is suitable for recording onto the magnetic recording medium

Magnetic recording/reproducing apparatus and method for determining magnetic recording condition

A magnetic recording apparatus includes: a magnetic recording medium having a recording surface on which a plurality of magnetic recording cells magnetically isolated from each other are arranged; a magnetic writing element recording information to the magnetic recording cells under a condition in accordance with setting information; a magnetic reading element reproducing information recorded in the magnetic recording cells; a memory storing the setting information for writing; and a processor for executing a program code. The program code includes a test module, responsive to a test write start signal, for repeating writing and reading test information by the magnetic writing and reading elements and calculating a quality index value representing quality of writing of the reproduced test information with the setting information changed, and a write module for selecting setting information with which the quality index value satisfies a predetermined condition, and writing the selected information in the memory.

Magnetic recording apparatus and magnetic recording evaluating apparatus

A magnetic recording medium includes: tracks each including a magnetic recording section in which information is recorded and a non-magnetic-recording section in which no information is recorded; and nonmagnetic guide sections magnetically separating the tracks from one another. The non-magnetic-recording section is formed integrally with nonmagnetic guide sections. The magnetic recording medium includes at least one pair of a first region in which at least a portion of each of the respective non-magnetic-recording sections of first and second tracks and a portion of a magnetic recording section of a third track coincide with one another at a position along a direction in which the tracks extend; and a second region in which at least a portion of each of the respective non-magnetic-recording sections of the first and third tracks and a portion of a magnetic recording section of the second track coincide with one another at a position along the direction in which the tracks extend.

Recording medium, recording/reproduction device and method for controlling recording/reproduction device

In an optical information storage medium reproduction apparatus () for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus () requires. With the arrangement, it is possible to prevent that the information recording layer closest to the reproduction-laser-incident surface is irradiated wrongly with reproduction laser having high reproduction laser power, thereby making it possible to obtain successful reproduction quality. That is, it is possible to realize the optical information storage medium reproduction apparatus () that can set optimum reproduction laser power and perform stable super resolution reproduction.

Examples of an electromagnetic field detecting element according to the present invention includes a substrate, a pair of electrodes, three insulation layers disposed on the substrate and between the electrodes. The three insulation layers are designed to have two or three different dielectric breakdown strength. At least two ballistic current paths are formed between the electrodes. With this structure, it is possible to perform at a room temperature a highly efficient electromagnetic field detection utilizing Aharonov-Bohm effect or Aharonov-Casher effect.

Electromagnetic field detecting element utilizing ballistic current paths

Growing community of inventors

Nishinomiya, Japan

Yoshiteru Murakami